Method to produce high densities of isolated atoms on support substrates
Described herein is a general scalable synthesis method for a high density of single metal atoms in a supported catalyst, supported isolated atoms featuring unique reactivity and the support materials determine the stability, electronic properties, and local environment which can be adjusted for targeted heterogeneous catalysis applications.
1. A method for producing heterogeneous single atom catalysts comprising:
dissolving at least one catalyst precursor in water to form a solution;
mixing at least one support substrate in the solution;
providing at least one metal precursor to the solution;
preventing precursor agglomeration via dissolving at least one non-water soluble chelating agent in at least one polar solvent and adding this to the solution;
providing and fixating precursor ions during catalyst activation;
anchoring at least one metal precursor to the at least one support substrate, wherein the at least one support substrate comprises TiO 2 and/or SiO 2 ; and
reducing the solution.
2. The method of claim 1 , further comprising yielding loadings of single atoms up to at least 1 atom per nm 2 .
3. The method of claim 1 , wherein the at least one non-water soluble chelating agent comprises 8-hydroxyquinoline.
4. The method of claim 1 , wherein strong electrostatic adsorption is not required to induce anchoring.
5. The method of claim 1 , wherein either anionic or cationic metal precursors are employed.
6. The method of claim 1 , further comprising conducting reduction at approximately 300° C.
7. The method of claim 1 , further comprising the at least one support substrate forming a pore framework.
8. The method of claim 1 , further comprising chelating metal ions or metal ion complexes with at least one ligand.
9. The method of claim 1 , further comprising producing at least one single atom on the at least one support substrate without the at least one support substrate having surface functional groups.
10. The method of claim 1 , further comprising removing the at least one chelating agent via high temperature treatment or washing with acetone followed by drying.
11. The method of claim 1 , further comprising adjusting the at least one chelating agent to the at least one metal precursor ratio to 2:1.
12. A method for producing heterogeneous single atom catalysts comprising:
dissolving at least one catalyst precursor in water to form a solution;
mixing at least one support substrate in the solution;
providing at least one metal precursor to the solution;
preventing precursor agglomeration via dissolving at least one non-water soluble;
chelating agent in at least one polar solvent and adding this to the solution;
providing and fixating precursor ions during catalyst activation;
anchoring at least one metal precursor to the at least one support substrate;
reducing the solution; and
further comprising chelating metal ions or metal ion complexes with at least one ligand.
13. The method of claim 12 , wherein the at least one support substrate comprises carbon or an oxide.
14. The method of claim 13 , wherein the carbon comprises carbon black, activated carbon, and/or diamond powder.
15. The method of claim 12 , further comprising yielding loadings of single atoms up to at least 1 atom per nm 2 .
16. The method of claim 12 , wherein the at least one non-water soluble chelating agent comprises 8-hydroxyquinoline.
17. A method for producing heterogeneous single atom catalysts comprising:
dissolving at least one catalyst precursor in water to form a solution;
mixing at least one support substrate in the solution;
providing at least one metal precursor to the solution;
preventing precursor agglomeration via dissolving at least one non-water soluble chelating agent in at least one polar solvent and adding this to the solution;
providing and fixating precursor ions during catalyst activation;
anchoring at least one metal precursor to the at least one support substrate;
reducing the solution and
further comprising adjusting the at least one chelating agent to the at least one metal precursor ratio to 2:1.